Method of and apparatus for refrigeration



H. L. DOHERTY METHOD OF AND-APPARATUS FOR REFRIGERATION Dec, 2, 1924. v

5 Sheets-Sheet 2 Filed July '7, 1920 1,518,053 H. L. DOHERTY METHOD OF AND APPARATUS FOR REFRIGERATION Filed July 7, 1920 5 Sheets-Sheet 5 .Dec. 2, 1924.

. M .fl w 4 z A 5 w/w a. J 7 4/ M 4 ww M H. L. DOHERTY METHOD OF AND APPARATUS FOR REFRIGERATION Fil ed July 7, 1920 s sheets-Sheet 4 A To all whom 2'25 may concern:

Patented Dec. 2, 1924.

HENRY L. DO'HER'I'Y, on NEW; YORK, N. Y;

' 'mn'rnon cram) APPARATUS ronnnrnrem'rronf Application filed July 7,

Be it known that I, HENRY L. DOHERTY,

a citizen of the United States of America,

residin at New York city, in the county of New ork, State of New York have in-' vented certain new and useful Improvements in Methods of and Apparatus for Refrigeration; and I- do hereby declare. the following to'be a full, clear, and exact description of the invention, such as willenable others skilled in the art, to which it appertains to make and use the same. 7

This invention relates to a method of and an apparatus for refrigeration, and more specificallyto a method and apparatus in which heat is abstracted from a space to be cooled. and the heat is in turn transferred to a body to be heated.

Low temperatures for refrigeration purposes may be obtained by two methods, one

of which is to place a mass of ice in the space Y to be cooled, and the other method is to 4 abstract the heat from the space to be cooled by mechanical and'thermodynamic 'means. The. first method has been the more widely used for domestic orhousehold refrigeration because of its simplicity, but it has several disadvantages as compared with the deteriorate or spoil in the interval.

second method. Among these disadvantages is the necessity for replacing the melt ed ice at frequent intervals and the danger,

Where the supply is irregular, or where the quantity necessary for a certain period. of

time is uncertain, that one charge of ice may that, the foods placed in the refrigerate ay not last until a fresh supply is receiv d and Added to these disadvantages there is a further dis advantagevthat the temperature ofthe refrigerator is of necessity limited by the melting point of the ice and cannot be varied or controlled to give the best temperature and humidity tion of food.

Mechanical or artificial methods pf refrigeration do not suffer from these defects,

since the supply of energy for' refrigeration may be made conti'nuou's and automatic and the temperature produced is independ-' ent of iny fixed 'points. Refrigeration by the "second method is also cheaper because of the comparatively lower cost ofthe ener the .combustion of one .cubic foot of gas conditions for the preservw' yused; Thus, one pound of ice absorbs on y about 144 B. t. u.-= in melting whereas] 1920. Serial No. 394,491.

yields energy equivalent to about 600 B. t. o A

Since the cost of a cubic foot of gas is but a fraction of the cost of a pound of ice, it

is therefore evident that it would be much a cheaper to use energy obtained by the combustion of gas even though a very small efficiency were obtained in the application of this energy for refrigeration purposes. Where fuel is also used for heating or other purposes, refrigeration may be obtained without the use of additional fuel, by applying a part of the energy of combustion to ab-- stract heat from the refrigerator and applying the heatreturned by the refrigerating operatlon for heatin water-or for other heating purposes. E ith such an arrangement, refrigeration may be obtained with very little, f any, expense over the cost of the heating operation alone, since there is a gain rather than a loss of heat to the system from the refrigerating operation.

The type of refrigerating machines used in'storage warehouses and otherlarge scale refrigerating plants re,-however, not suitable for adaptation 0 domestic or household purposes, because they are cumbersome and require constant attention and a certain amount of engineering skill in their operation. A refrigerating plant suitable for small sized, or household, purposes must be simple in construction and require little or no attention in daily operation. It should be so arranged that upon supplying power tion is to provideamethod of refrigeration in which energy is applied to produce a refrigerating eifectand the heat given up by the refrigerating operation is applied to produce useful heating effects. Another object of the invention is to pro-, vide a refrigerating apparatus'in which energy isapplied to produce a refrigerating effect and the heat given up in the refrigerating operation is used ,to produce useful heating eflt'ects.

Another objectof the present invention is to provide a simple and compact refrigerating' apparatus for domestic purposes.-

' tion and defined in the claims.

The various features of the-invention are shown in the accompanying drawings, in which:

Fig. 1 is an elevation partly in'section, of a refrigerating apparatus embodying a preferred form of the invention; I

Fig. 2 is a detailed sectional view of a pressure boiler or generator of the refrigerating apparatus for driving the ammonia gas out of solution.

Fig. 3 is a detailed sectional view of, a hot Water heater in which water is heated by the condensation of ammonia gas under pres sure; I r

Fig. 4 is a detailed sectional view of an absorption chamber for ammonia gas and shows the lower portion of the water heater illustrated in Fig. 3;

Fig. 5 is a detailed sectional view of the ammonia expansion valve; and t Fig. 6 is a detailed sectional view of the gas supply regulating valve.

Inthe present invention the combustion of fuel gas is used as a source of energy for refrigeration and for heating water in a hot wvater suppl system. For this purpose a saturated so ution of ammonia gas is heated in a boiler capable of withstanding a' high pressure and the ammonia is thereby driven out of solution. The ammonia gas driven out of solutionby the heating is condensed under pressure to liquid ammonia. When a sufiicient amount of ammonia has been driven out 01 solution andcondensed, the residual liquor is removed from the boiler and cooled. The condensed ammonia is expanded through expansion and refrigeration coils placed in the medium to be cooled, is thereby reduced in temperature and cools the medium by the abstraction of heat therefrom. The expanded ammonia isthen reabsorbed in thecooled ammonia liquor and is returned with the liquor to the pressure boiler or generator and the cycle of operations is repeated.

The heat given ofi by the condensation of the ammonia gas, by the absorption of am- -monia gas and in the cooling of the ammonia liquor is used to heat water in a hot water supply system in such a manner that the water is successively heated by fluids of increasingly higher temperature. In this manner, the heatof con'ibustion supplied to the generator by the gas flame is transferred to the hot water heating system and an additional amount of heat absorbed by the cooled ammonia gas in passing through the refrigerating coils is also returned to the water heatin system when the ammonia gas is redissolve in ammonia liquor.

In the illustrated embodiment of the in vention shown in the drawings, a pressure boiler or generator 10 (Figs. 1 and 2) is heated by a gas flame from a burner 12 placed beneath the generator. The products of combustion from the burner 12 pass up wardly between the generator 10 and a surrounding mantel 14 and are exhausted from the upper part of the mantel 14 through a chimney 16. The generator 10 is partly filled with a concentrated solution of ammonia in water, and as the boiler is heated, the ammonia is driven out'of solution and rises through a vapor pipe 18 (Figs. 2 and 3) which has a comparatively large diameter to permit entrained water to drop back to the generator. From the upper end of the vapor pipe the ammonia gas passes through a check valve 20 (Fig. 3) into a cooling coil 22 enclosed within a hot water heater 24. As additional quantities of ammonia gas are driven off, the pressure of the ammonia in the generator 10 and in the condensing coil 22 continually increases until it reaches a pressure of approximately 175 pounds per square inch. At this pressure, the ammonia condenses in the lower part of the coil 22 thereby raising the temperature of the water surrounding the coil to approximately F. As additional quantities of ammonia are driven from the generator 10 into the coil 22, the ammonia is cooled in passing through the upper part of the coil which is surrounded by partly heated water and as it reaches the lower part of the coil it is cooled to a temperature at which it condenses and forms a body of liquid ammonia in the lowermostpart of the coil. The condensed ammonia isprevented from passing back into the generator 10 by the check valve 20. w From the lower part of the coil 22 the liquid ammonia is withdrawn through a pipe 26 to an expansion chamber 28 of a thermostatically controlled expansion valve 30. In the expansion chamber 28 the pressure on the liquid ammonia is released and the ammonia thereupon vaporizes and is cooled to a very low temperature. The cooled expanded ammonia gas flows from the expansion chamber into a cooling coil '32 positioned within a cooling chamber in a refrigerator 34. In passing through the coil 32, the ammonia cools .the refrigerator and is itself heated by the abstraction of heat from the refrigerator. The extent to which the ammonia gas is heated by this operation and the resulting temperature of the gas depends upon the temperature conditions in the refrigerator and is a measure of the amount'of amofammonia. gas. When a temperature is is heated in driving out the dissolved ammonia as it becomes continually weaker in ammonia and a higher temperature is required for (lIlVlIlg out additional quantities reached at which a considerable amount of water 15. vaporized with the ammonia, a

thermostatically controlled valve 44 closing the projecting end of the rod.

the end of a liquor draw-off pipe 46 exte'nding into the generator 10 (Fig. 2) is opened and the liquor is forced into the draw-off pipe by the gaseous pressure in the upper part of the generator. The liquor passes throughthe pipe 46 into a cooling coil 48 iorming a continuation of the pipe 46 in the heater 24 and enters the absorption chamber 42.

' The opening of the valve 44 in the generator 10 is controlled by means of a thermostat 50, the lower end of which is connected by means of a rod 52 to the valve 44 and the upper cap 54 of which is adjustably supported by a rod 56 extending from the cover 58 of the generator. The rod 56 is threaded in the cap 58 and its outer end 60 1s squared so that the position of the rod' 56 may be adjusted vertically by turning the squared portion 60, to vary the temperature at which the valve 44 opens. Accidental turning or tampering with the position of the rod is prevented by a removable cap 62 covering N The thermostat and rod are'alsoprotected from lateral movement within the generator 10 by a casthrough the pipe 46 is so slow that considerable time would be required for the return of all of the liquor from the'absorption chamber 42 to the generator. As the first portions of returning saturated liquor come into contact with the heated walls .oft'he generator, there is an immediate generation of ammonia gas and building up of pressure which'would prevent further inflow of liquor. To hasten the return of the cold s'aturated liquor to the generator 10, therefore,

as under ressure is b -oassed from the g P y pipe 18 to the absorbing chamber 42 through a by-pass pipe 68 (Figs. 1 and 4) and the cooled liquor is permitted to immediately fall through the return pipe 40 which is of a comparatively large diameter.

The liquor is not admitted directly into the generator because of the sudden generation of pressure, but is led into an intermediate storage tank 70 which is of suflicient size to store all of the liquor and is in communication with the generator 10 through a liquor return pipe 72 and a pressure equalizing pipe 74. The diameters of the pipes 40, 72 and 7 4 are so proportioned that the liquor flows from the absorption chamber 42 to the storage chamber 70 in a Very short time, but the pipe 7 2 leading from the storage tank to the generator, is of such a small diameter that very little of the liquor will flow from the tank intothe generator during the time of filling the tank 7 O. As the liquor flows from the tank 70 into the generator 10, a pressure is immediately built up which is transmitted to the tank 70 through the pressure equalizing pipe 74, but the liquor in the tank is prevented from flowing back to the absorber 42 by means of a check valve 76 in the tank 70 (Fig. 2) closing the end of the pipe 40. The pressure in the generator does not prevent the inflow of liquor from the tank 7 through ing'64 having slots 66 to permit access of the by a compound valve which is opened .when

liquor to the thermostat 50.

The liquor outlet pipe 46 arid the cooling the liquor in the absorption chamber 42 reaches a definite level and is maintained coil 48 have a sm'all. diameter to prevent a in open position until the chamber is emprapid flow of liquor and to give suflicient tied of li uor. This valve comprises an time for the liquor to be cooled while passing outer shell 8 (Fig. 4) positioned in a valve through the coil 48.; When all of the liquor chamber '80 in the top of the absorption has been transferred from the generator 10 chamber and is arranged to close an opento the absorption chamber 42, the pressures ing 7 9 between the absorption chamber and in the generator and absorption chamber, the valve chamber 80. The valve chamber tend to equalize by the passage of ammonia 80 communicates with the by-pass pipe 68 gas from thegenerator through the pipe 46, through a series of lateral openings-84 in and permit the liquor saturated with amthe 120p 85 0f the valve chamber. The shell monia in the absorption chamber 42 to fl 78 is vertically movable in the valve cham-v back by gravity into the generator. ber and is maintained in an upright posi- Because of the small diameter of the pipe tion by means of a stem. 86 sliding in a 46, the equalization of piessurebetween the seeve 88 depending from the top, of thegenerator 10 and the absorption chamber 42 valve chamber. The lower end of the shell 7 8 is provided with an opening 90 which is in turn closed by a solid valve 92. The sides of the shell 78 are also provided with a series of openings 94 which transmit ressure from the valve chamber 80 and y-pass pipe 68 to the top of the solid valve 92. The-valve 92 is provided with a downwardly extending stem 96 which is in turn rigidly connected through a hollow rod 98 tofa float 100 in the lower part of the absorption chamber. As the absorption chamber 42 is filled and liquid submerges the float 100, thebuoyant effect of the float exerts a lifting force on the valve 92 which is sufliqient to support the weight of the valve, but is not suflicient to lift the valve against the pressure in the valve chamber 80 acting downwardly on the valve. As the level of the liquor in the absorption chamber rises, it submerges a second, larger float 102 loosely surrounding the rod 98 and vertically movable in relation thereto. As the liquor rises upwardly around the float 102 it lifts the float and compresses a spring 104 between a disc 106 on the upper face of the float and a disc 108 rigidly mounted on the rod 98. The spring 104 is compressed until the force of compression added to the buoyant force of the float 100 is sufficient to lift the valve 92. When this occurs, the spring 104 throws the valve 92 upwardly against the top of the shell 78 with sufficient force and momentum to lift the shell 78 from the valve seat opening 79. The pressure between the valve chamber 80 and the expansion chamber 42 is thereupon immediately equalized and the valve held in its upper position. A rapid flow of gas from the pipe 18 through the by-pass pipe 68 and valve opening 7 9 is thereby permitted and the liquor rapidly falls by gravity through the outlet pipe to the storage chamber 70. As the liquor falls below the float 102, the valve 92 and shell 7 8 are supported by the float 100, since there sorption of ammonia gas in the cool liquor in the absorber 42 and by the transferrence of heat from the hot liquor and gases in the coils 22 and 48 in the upper part of the heater 24. The temperature to which the water can be raised by the condensation of the ammonia gas in the coil 22 is. limited to approximately F. which is the condensation temperature of ammonia under a pressure of 165 pounds, which is the maximum pressure'employed in the system. The absorption of ammonia gas by the cool liquor in the absorption chamber 42 is also an exothermic process which ma be carried out at temperatures somewhat a ove 85 F. It is desirable, however, not to carry out the step of absorption at a very high temperature because the solubility of ammonia in the liquor decreases with the temperature, the rate of absorption isaccordingly decreased and a weaker solution' of ammonia is obtained. The temperature obtained by the transferrence of heat froin the upper part of the coils 22 and 48 is, however, limited only by the temperature and thermal capacity of the hot liquor and gases. To obtain a temperature of the hot water suitable for domestic use, the water being heated is therefore heated first by the condensing ammonia, then by the absorption of ammonia in the cool liquor and finally by the transferrence of heat from the hot liquor and hot. ammonia gases in the boils 22 and 48.

To this end, the water is drawn from a reservoir or stand boiler 110 through a circulating pipe 112, and branch pipe 114 to the bottom of the heater 24. The circulating water passes upwardly through the heater 24 being heated first by the condensing ammonia in the lower part of the coil 22 and still further heated by the heat given up in the absorption of ammonia in the chamber 42, and finally by the direct transfer of heat from the icoils 48 in the upper part of the coil 22. The heated water leaves the upper part of the chamber 24 and returns to the stand boiler through a return pipe 116. The stand boiler is gradually filled with hot- Water which may be removed from the upper part of the'boiler, through a drawolf pipe 118, a fresh supply being introduced into the lower part of the boiler by the inlet pipe 120. The stand boiler may be also connected to other heating means through the branch pipe 122 when the refrigerator is not in operation.

Since the. vapor pressure of ammonia gas rises very rapidly with small increases in temperature above 85 F, the temperature in the heater 24 should be so controlled that the lower portion of the heater will not rise above approximately 85 F. The heater is therefore provided at its upper end with a temperature controlled release valve 124 shown in detail in Fig. 3 which opens the heater into direct communication with a waste pipe 126 when the temperature rises ill) above a definite limit. The temperature of the water is measured by an expansion thermostat 128, the lower end of which is rigidly held in an enclosing case 130 suspended from a depending flange 132 on the top of the heater 24. The case 130 is provided with openings 134 and 136 at its lower and upmostat expands and contracts and imparts.

its motion through a valve stem 140 to a valve 142. When the temperature of the I thermostat is below a definite safe limit, the

valve 142 is pressed downwardly onto the valve seat 144 by means of a spring 146,, placed between the upper face of the, valve and a vertically adjustable plate 148. When the temperature of the water rises above a definite limit, the expansion of the thermostat 128 lifts the valve 142 from its seat against the actioniof the spring 146 and permits the water to flow through openings 150 in the flange 132, through thevalve seat opening 144, and the openings 152 in the valve 142 to the Waste pipe 126. A fresh supply of cool water is thereupon drawn stand boiler 110 and flows through the pipes 112 and 114 to the lower portion 0 the heater 24, thereby cooling the lower portion of the heater. The pressure exerted by the spring 146 on the valve 142 may be adjusted by means of three adjusting screws 154 acting on the plate 148. The valve stem 140 is threaded on the valve 142 and the position of,the thermostat top 138 and the valve 142, may be adjusted by rotating the valve stem 140 by means of a rotatable screw 156, slidably connected with the rod 140.

The temperature in the refrigerator 34 is also maintained Within definite limits by nieansof a thermostat'158 in the chamber 36 of the valve 28, as shown in detail in Fig. 5. The upper end 160 of the thermostat I is fixedly supported by a yoke 162 which is in turn supported by a rod 164 threaded at 166 in the bottom of the chamber-36. The end of the rod 164 extending through the bottom of the chamber 36 is squared at 168 to permit the rod to be turned and adjusted in a vertical position. The lower end 170 of the thermostat is connected by means of a yoke 17 2 to a valve stem 174 extending into the expansion chamber 30 of the valve, and controls, the admission of liquid ammonia from the pipe 26 to the chamber 30. The liquid ammonia entering the valve 28 through the pipe 26 is received in a' small valve chamber 176 forme'din the upper part of the chamber 30 and closed'at its lower end by a plate 178. The plate 17 8 is provided with a small opening 180 forming a valve seat for the valve member 174. When the temper; ature of the refrigerator rises above the max imum limit, the exhaust ammonia gas delivered to the chamber 36 through the coils '32 causes the thermostat 158 toexpandand move the lower end 170 of the thermostat downwardly. This downward movement is transmitted through the .yoke 172 to (the valve 174 and the valve is drawn away from the opening 180 permitting the liquid am monia to flow freely from the valve chamber 17.6 to theexpiansion chamber 30 and the cooling coils 132. As the temperature of the refrigerator falls below a definite limit, the waste gases delivered to the chamber 36 from the coils 32 become cooler and cause the thermostat 158 to contract. The lower end 170 of the thermostat is thereupon drawn upwardly and forces the valve 174 to contact with the valve opening 180 to close or partly close the opening 180 and stop ornearly stop the inflow of liquid ammonia. The temperature-limits at which the valve 174 is moved can be adjusted by turning the .squared end 168 of the thermostat support means of a. cap 182 covering the end of the .rod. The flow of ammonia may also be through the pipe 120 to the bottom of the built upv in the system if the heating of the generator 10 were continued. .A valve device is therefore provided to shut off the supply of gas to the burner 12 and to thereby stop the operation of the apparatus when the pressure of ammonia in the system increases beyond a certain point. To this end, the gas-for the burne'r12 is led from a main 194 through a pressure safety device 196 to a pipe 198 leading directly to the burner 12 (Figs. 1 and 6). The safety device is divided into a high pressure chamber 200, which communicates with the ammonia condensing coil 22 through a connecting pipe 202, and a gas compartment 204 through which gas flows to the burner supp-1y pipe 198. The supply of gas from the main. 194

to the gas chamber 204 isregulatod by a cap 212 of the chamber 204 and a disk 218 which is threaded on the stem 214. The spring 216 tends to force the disk 218 downwardly and to thereby carry the stem 214 -dinarily held in open position by a spr 'ing 216 which is confined between the closing "position.

and the valve 206 downwardly into open in the chamber 200 increases beyond a certain definite point, the valve stem 214 and disk 218 are moved upwardly against the action of the spring 216 and lift the valve 206 upward to close the opening 208.

Because of the high pressure normally existing in the chamber 200 and the necessity of absolutely preventing any escape of the ammonia from the chamber 200 into the chamber 204, packing devices can not be relied on for preventing the escape of gas around the elements through which movement istransmitted from the chamber 200 to the valve 206. To avoid any possibility of an escape of gas from the chamber 200, a device which forms a hermetic seal between the chambers 200 and 204 is employed. The hermetic sealing device consists of a corrugated tube 220 hermetical-' 1y attached at its upperend to a partition dividing the chambers 200 and 204 and hermetically closed at its lower end by a movable bulb 224. The valve stem 214 is extended downwardly through an opening 226 in the partition 222 until it reaches the movable plug 224. The action of the spring 216 transmitted through the disk 218 and valve stem 214 forces the plug 224 downwardly to its lowermost position. When a pressure is built up in the pressure chamber 200, the action of the spring 216' is opposed, the corrugated tube is compressed and the plug 224 is lifted upwardly against the action of the spring 216. The tension of the spring is so adjusted that when the pressure in the condensing coil 22, and accordingly in the pressure chamber 200, is increased beyond a certain limit, the pressure of the gas will force the supply of gas to the burner 12. The tension on the spring 216 and accordingly the pressure at which the valve 204 will be opened, is adjusted by rotating the valve stem 214 on the disk 218 and valve 206. For this purpose the gas compartment 210 is closed by means of a removable cap 228. To adjust the position of the valve 206 and disk 218 on the valve stem 214, the cap'228 is removed and the valve stem 214 is rotated by means of a screw driver inserted through the opening in the top of the compartment 210. A small bleed or pilot passage 230 is provided in the cap 212 through which a small amount of gas will be allowed to pass when the valve 204 is in fully closed position to guard against the escape of unburned gases due to successive closing and opening of the valve204. The rate at which gas may pass through the pilot passage 230 is controlled by a needle valve 232.

By means of the method and apparatus described above all of the heat energy absorbed by the generator 10 from the flame However, when the pressure with-.

of the burner 12 is transmitted to the hot water heater 24. The efliciency of the heater 24, considered purely front the hot water heating standpoint, is equal to the efliciency of the generator 10 and is not decreased in any way by the refrigerating operation. In fact, some heat is absorbed from the refrigerator 34, carried to the hot water heater 24 and added to the heat which is introduced to the heater 24 from the generator 10. This additional amount of heat is not obtained as a result of a loss of any heat given up to the generator 10, but is obtained by a transfer of heat from the comparatively colder refrigerator to the comparatively warmer hot water heater brought about through a. drop in temperature, and correspondingly a drop in the potential of the available energy imparted to the generator 10 from the gas flame of the burner 12. By taking advantage of the different temperatures at which the operations of condensing and absorbing ammonia and of cooling the ammonia liquor are carried on, the apparatus is arranged to heat the water passing from the hot water heater 24 to a much higher temperature than would be possible if but a single operation were relied upon for this purpose, and to thereby combine a high efiiciency of operation With a maximum temperature obtained in the heating of water. i

, Having described the invention, what is claimed as new is: p

'1. A method of heating Water and producing refrigeration, which comprises distilling ammonia gas from an ammonia solution under pressure by the application of heat, condensing under the said pressure the ammonia gas through heat interchange with a body of Water to be heated, circulating the said body of water to a chamber from which it may be withdrawn for domestic use, regulating the heating of the ammonia solution in accordance with variations in pressure of the ammonia gas undergoing distillation,automatically transferring the hot residual ammonia solution into heat transferring relationship with the said body of water when the said solution reaches a delinite predetermined temperature and thereby cooling the solution, automatically withdrawing a portion of the said body of water orator for driving ammonia gas out of an ammonia solution under pressure, a condenser'in said circulating water heater for condensin said ammonia gas under pres- Sure and l ieating water in said circulating heater, means for automatically removing the entire body'of exhausted ammonia/liq nor from the heating generator at one time, means for ,cooling said exhaust liquor comprising a single container, means for expanding the condensed ammoniagas in heat absorbing relation for refrigeration, means for absorbing the expanded ammonia gas in said cooled ammonia liquor, and means for returning ammonia solution to said generator.

3. An apparatus for refrigerating andfor heating water, comprising a water storage tank, a circulating water heater connected to said tank, a pressure boiler, a vapor pipe leading from the top of said 'boiler through said water heater and forming a condensing coil therein, a check valve in said vaporpipe, a waste liquor pipe leading irom the bottom of said pressure bo ler through said heater and forming a coil 'in said heater, an absorbing chamber in said water heater below the coil intsaid liquor; pipe and into which said liquor pipe delivers, an expansion 'and cooling coil,

a pressure reducing valve connectingv said vapor pipe to said expansion coil,

'. a; return pipe from said cooling coil to said absorbing chamber, a bypass from said vapor pipe t o said absorption chamber,

a float controlled. valve in said absorption chamber controlling the by-passing of am L monia to said absorption chamber, a re turn pipe from said absorption chamber to said pressure boiler, and a chcck valve in said return pipe.

Q 4. An apparatus for refrigerating and for heating. water, comprising a hot water storagetank, a circulating water heater connec d to said tank, a pressure boiler, a

vapor pipe-to said expansion coil, and a return pipe lea'ding'from said expansion coil to sald absorption chamber, a return pipe from said'absorption chamber to said pressure boiler, and a check valve in, said return pipe. a i

5. A combination refrigerator and hots water heater which comprises a generator for'driving ammonia out of solution under pressure, awater heater, a cooling and condensing coil in said water heater arranged to receive and condense ammonia gas. from said generator, a liquor cooling coil in saidwater heater, means for automatically transferrmg llquor from said generator, to said liquor cooling collwhen the liquor in sa d vgenerator reaches a definite temperature, an

absorption chamber in said" water heater connected to one end of said l quor cooling coil, a thermostatically controlled valve governing the end of said ammonia condens-' Ping coil and having a thermostat chamber connected to said absorption chamber, an

ammonia expansion coil connected through said thermostatically controlled valve to said ammonia condensing coil, and means for returning ammonia liquor from'said absorption chamber to said generator-when the pressures in the absorption. chamber and generator 'ha ve become equalized, said means comprising a pipe, containing a check valve seated by pressure on the generatorside thereof, a tank between said check valve ard generator, and a liquor connection and a pressure equalizing connection between said tank and said generator. 6. A combination refrigerator and hot t'er heater comprising a generator for eating'an'd driving ammonia out of an ammonia solution, a hot water heater, an ammonia condensing .coil leading from said generatorand extending through said hot water heater, an ammonia absorber in said hot water heater, a cooling coil in said hot water heater outside of .said absorber, said cooling coil being connected at one end'to said generator and, at the other end to said "absorber, automatic means for expanding ammonia from said condensing coil to pro-.

duce refrigeration thereby, automatic means for transferringweak ammonia liquor from rap "pipe leading from the top-of said pressaid generator to said absorber through said sure boiler thrusaid circulating Water heater, an exhaust liquor pipe leading from the bottom of said pressure bo |l er into said c rculatmg water heater and forming a coil in the heater, an absorption chamber in said water heater below the co1l'E-m said liquor:

pipe and into which said liquor pipe de liversfa thermostatically controlled valve in said pi'essure boiler governing the en- ,trance of said exhaust liquor pipe, a check valve in said va or pipe, an expansion coil,

"a differential pressure valve connecting said generator 'in accordance-with variationsia pressure of the ammonia gas intermediate said generator and said expanding means.v

In testimony whereof I aflix my 'signature. v 5 I H, ENB.Y L; DOHE'RTY. 

